P1268: ALLOGENEIC HEMATOPOIETIC CELL TRANSPLANTATION FOR HIGH-RISK MYELODYSPLASTIC NEOPLASMS: A RETROSPECTIVE, SINGLE-CENTER ANALYSIS
Authors: Jan Christian Schröder, Philipp Faustmann, Jan Frederic Weller, Christoph Faul, Claudia Lengerke, Wolfgang A. Bethge
Journal: HemaSphere (2023)

Topic: 22. Stem cell transplantation - Clinical Background: Allogeneic hematopoietic cell transplantation (HCT) represents the only curative treatment option for patients with high-risk myelodysplastic neoplasms (MDS). Selection of HCT candidates and conditioning approaches is aided by prognostic scores and retrospective analyses. Patients with MDS are heterogeneous. Recent changes in the WHO classification of myeloid neoplasms acknowledge that high-risk MDS and myelodysplasia related AML subgroups are related disease entities. The value of hematologic remission prior to HCT in high-risk MDS and AML myelodysplasia related are unclear and remain a matter of debate. Aims: We report here single-center real-world outcome data of MDS patients undergoing allogeneic HCT. Long-term outcomes including survival, relapse free survival, relapse and graft-versus-host disease (GVHD) are analyzed with the aim of identifying patient, disease, and treatment variables that may predict clinical outcome after transplantation. Methods: We report 130 patients diagnosed with MDS and transplanted between 2010 and 2022 at University Hospital Tübingen. Median age was 59.5 years (range 26 to 77 years) and 43.8% of patients were female. 23.7% of patients had a high and 30.1% of patients had a very high IPSS-R score, respectively. Donor sources were matched (8/8) related donor in 23.8%, matched (8/8) unrelated in 52.3%, mismatched (7/8) in 20%, and haploidentical in 3.8% of patients. Conditioning regimens were myeloablative in 8.5%, FLAMSA-based reduced intensity conditioning (RIC) in 27.7%, and RIC in 63.8% of cases. Results: The median follow-up after HCT was 54 months. Kaplan-Meier estimates for overall survival (OS), event-free survival and non-relapse mortality at 3 years were 63%, 54.4% and 17.8%. The cumulative incidence of relapse, acute GVHD grade II to IV and chronic GVHD were 32.7%, 32.8% and 43.7%, respectively. OS was significantly worse in patients with bone marrow blast counts exceeding 10% before treatment (p=0.03), IPSS-R greater than 5 (p=0.004) or IPSS-M greater than 1.5 (p=0.03). Interestingly, induction treatment with azacytidine before HCT also associated with lower OS (p=0.01). In contrast, no significant differences in OS were noted between matched (8/8) vs. mismatched (7/8) donor (p=0.5), between myeloablative/intensified conditioning vs. reduced-intensity conditioning (p=0.91), performance score (p=0.6), year of HCT before vs. after 2016 (p=0.82). Age and HCT-CI impacted outcome by trend, without reaching statistical significance in this cohort (p=0.07 and respectively p=0.09). Summary/Conclusion: Main determinants of transplant outcome were the degree of blast increase and adverse cytogenetics and molecular genetics as demonstrated by the strong prognostic significance of high or very high IPSS-R and IPSS-M scores. In contrast, age, performance score, comorbidity score, and year of transplantation were not significantly correlated with survival. Pre-treatment with azacytidine before HCT associated with worse outcome. Keywords: Azacitidine, Prognostic factor, Myelodysplastic syndrome, Allogeneic hematopoietic stem cell transplant